The purpose of this study is to expand understanding of the effects of cannabis on driving performance with and without the presence of low levels of alcohol.

This project will involve the development a of a protocol and driving environment that is sensitive to the effects of cannabis on driving performance by building on prior driving situations used previously for testing the effects of alcohol on driving.

Used as an assessment of risk perception, risk taking and impulsivity. Performance on this task as well correlations between cannabinoid concentrations and driving performance and effects on the Rogers gambling task will be measured.

BART assesses risk-taking behavior in an objective manner. Performance on this task as well correlations between cannabinoid concentrations and driving performance and effects on the BART will be measured.

Individuals will be recruited who are currently users of cannabis and alcohol to participate in this study. They will undergo a physical exam at screening. There will be six study visits where the subject will arrive at the Clinical Research Unit(University of Iowa Hospitals & Clinics) the night before dosing. At each visit subjects will be receive one of the following six dosing regimens: placebo alcohol with placebo cannabis; placebo alcohol with low-dose cannabis, placebo alcohol with higher-dose of cannabis, low dose alcohol with placebo cannabis; low dose alcohol with low dose cannabis, low dose alcohol with higher-dose of cannabis. After dosing, participants will have provide saliva samples and blood drawn periodically to check cannabis levels and will complete a driving simulation. After completing the drive, additional saliva samples and blood draws will occur and participants will be monitored until it is safe to transport home.

Eligibility

Ages Eligible for Study:

21 Years to 55 Years

Genders Eligible for Study:

Both

Accepts Healthy Volunteers:

Yes

Criteria

Inclusion Criteria:

Healthy adult (age 21-55) men and women, based on medical and psychological evaluation

Currently valid unrestricted (except for vision correction) US driver's license

Licensed driver for at least the past two years

Drove at least 1300 miles in the past year, by self-report

Live within an 80 mile radius of NADS

Available for an overnight stay followed by a full-day study session for six sessions

Must be considered a light or moderate drinker according to Quantity-Frequency-Variability Scale (QFV)

Cannabis use with a minimum frequency averaging at least one day per quarter and no more than three days a week during the three months prior to study entry

Female subjects with reproductive potential must agree to use (and/or have their partner use) one (1) acceptable method of birth control beginning at the screening visit throughout the study (including intervals between treatment periods/panels) and until 2 weeks after the last dose of study drug in the last treatment period. Acceptable methods of birth control include the following: intrauterine device (IUD-with or without local hormone release), diaphragm, spermicides, cervical cap, contraceptive sponge, oral contraceptives or condoms. Abstinence is an alternative lifestyle and subjects practicing abstinence may be included in the study.

History of a clinically significant adverse event associated with cannabis or alcohol intoxication

Donation of more than 450 mL of blood within 14 days of study drug administration

If female, pregnant or nursing

Currently interested in or participating in drug abuse treatment, or participated in drug abuse treatment within 60 days preceding study enrollment

Currently taking drugs that are contraindicated for use with study drugs

Requires any special equipment to aid in driving (ex. pedal extensions, hand brake or throttle, spinner wheel knobs or other non-standard equipment)

Significant history of motion sickness or demonstrates significant simulator sickness during practice drives at screening (SSQ). Subjects must have scores below the following values on the SSQ: Nausea < 21, Oculomotor <32, Disorientation < 15, and Total Score < 32.

Current alcohol or cannabis use disorder, as identified by the Alcohol Use Disorders Identification Test for alcohol or Cannabis Use Disorders Identification Test for cannabis.

History of any illness that, in the opinion of the study investigator, might confound the results of the study or pose an additional risk to the subject from study participation

Prior participation in a driver impairment or distraction-related research study conducted at NADS that uses the same base drive.

Contacts and Locations

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study.
To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01620177